Human Papillomavirus (HPV) mainly causes warts in skin and mucosa. HPV types are divided into high-risk types and low-risk types depending on their association with tumorigenesis. Among them, infection by high-risk HPV types has been demonstrated to be the leading cause of genital cancer including cervical cancer in women; and low-risk HPV types mainly cause condyloma acuminatum. The most effective way to prevent and control HPV infection is to vaccinate HPV vaccines, particularly vaccines against high-risk HPV types causing cervical cancer.
Major capsid protein L1 of HPV has the characteristic of self-assembling into hollow Virus-Like Particle (VLP). HPV VLP has a symmetrical icosahedral structure composed of 72 pentamers of major capsid protein L1 (Doorbar, J. and P. H. Gallimore. 1987. J Virol, 61(9): 2793-9). HPV VLP is highly similar to natural HPV in terms of structure, retains most of the neutralizing epitopes of natural virus, and can induce the generation of high-titer neutralizing antibodies (Kirnbauer, R., F. Booy, et al. 1992 Proc Natl Acad Sci USA 89(24): 12180-4).
However, the existing studies show that HPV VLPs mainly induce the generation of neutralizing antibodies against the same HPV type, produce the protective immunity against the same HPV type, and only have low cross-protective effect among a few highly homologous HPV types (Sara L. Bissett, Giada Mattiuzzo, et al. 2014 Vaccine. 32:6548-6555). Therefore, the existing HPV vaccines have a very limited protection range. In general, VLP of one HPV type can only be used to prevent infection by the same HPV type. In this case, if it needs to broaden the protection range of HPV vaccines, the only way is to add VLPs of more HPV types in vaccines. Currently, the commercially available HPV vaccines, including Gardasil® from Merck (which is a quadrivalent vaccine against HPV16, 18, 6 and 11), Cervarix® from GSK (which is a bivalent vaccine against HPV16 and 18), and Gardasil®9 from Merck (which is a 9-valent vaccine), are prepared by combining VLPs of multiple HPV types. However, such a solution would greatly increase the production cost of HPV vaccines, and might cause safety problem due to an increase in immunizing dose.
Therefore, it is urgent in the art to develop HPV virus-like particles capable of inducing the generation of protective neutralizing antibodies against multiple HPV types, so as to prevent infection by multiple HPV types, and a disease caused by the infection, such as cervical cancer and condyloma acuminatum, more economically and effectively.
Contents of Invention
The invention is at least partially based on the inventors' surprising discovery: after substitution of a specific segment of L1 protein of Human Papillomavirus (HPV) Type 11 with the corresponding segment of L1 protein of a second HPV type (such as HPV6), the mutated HPV11 L1 protein thus obtained can induce the generation of high-titer neutralizing antibodies against HPV11 and the second HPV type (such as HPV6) in organisms, and its protection effect is comparable to that of a mixture of HPV11 VLP and VLP of the second HPV type, its protection effect against HPV11 is comparable to that of HPV11 VLP alone, and its protection effect against the second HPV type (such as HPV6) is comparable to that of the VLP of the second HPV type alone.
Therefore, in one aspect, the invention provides a mutated HPV11 L1 protein or a variant thereof, wherein as compared with wild type HPV11 L1 protein, the mutated HPV11 L1 protein has the following mutations:
(1) N-terminal truncation of 3-6 amino acids, for example, 3, 4, 5 or 6 amino acids; and
(2) (a) substitution of amino acid residues at positions 170-179 of the wild type HPV11 L1 protein with amino acid residues at the corresponding positions of a L1 protein of a second type of wild-type HPV; or
(b) substitution of amino acid residues at positions 346-351 of the wild type HPV11 L1 protein with amino acid residues at the corresponding positions of a L1 protein of a second type of wild-type HPV; or
(c) substitution of amino acid residues at positions 119-140 of the wild type HPV11 L1 protein with amino acid residues at the corresponding positions of a L1 protein of a second type of wild-type HPV;
and, the variant differs from the mutated HPV11 L1 protein only by substitution (preferably conservative substitution), addition or deletion of one or several (e.g. 1, 2, 3, 4, 5, 6, 7, 8 or 9) amino acids, and retains the function of the mutated HPV11 L1 protein, i.e. capability of inducing generation of neutralizing antibodies against at least two HPV types (e.g. HPV11 and HPV6).
In some preferred embodiments, the mutated HPV11 L1 protein has 3, 4, 5 or 6 amino acids truncated at N-terminal, as compared with the wild type HPV11 L1 protein.
In some preferred embodiments, the mutated HPV11 L1 protein has 4 amino acids truncated at N-terminal, as compared with the wild type HPV11 L1 protein.
In some preferred embodiments, the second type of wild-type HPV is HPV6. In some preferred embodiments, the amino acid residues at the corresponding positions as described in (2) (a) are amino acid residues at positions 169-178 of a wild type HPV6 L1 protein.
In some preferred embodiments, the second type of wild-type HPV is HPV6. In some preferred embodiments, the amino acid residues at the corresponding positions as described in (2) (b) are amino acid residues at positions 345-350 of a wild type HPV6 L1 protein.
In some preferred embodiments, the second type of wild-type HPV is HPV6. In some preferred embodiments, the amino acid residues at the corresponding positions as described in (2) (c) are amino acid residues at positions 119-139 of a wild type HPV6 L1 protein.
In some preferred embodiments, the wild type HPV11 L1 protein has an amino acid sequence as set forth in SEQ ID NO: 1.
In some preferred embodiments, the wild type HPV6 L1 protein has an amino acid sequence as set forth in SEQ ID NO: 2.
In some preferred embodiments, the amino acid residues at positions 169 to 178 of the wild type HPV6 L1 protein have a sequence as set forth in SEQ ID NO: 35.
In some preferred embodiments, the amino acid residues at positions 345 to 350 of the wild type HPV6 L1 protein have a sequence as set forth in SEQ ID NO: 36.
In some preferred embodiments, the amino acid residues at positions 119 to 139 of the wild type HPV6 L1 protein have a sequence as set forth in SEQ ID NO: 37.
In some preferred embodiments, the mutated HPV11 L1 protein has an amino acid sequence selected from the group consisting of: SEQ ID NOs: 6, 7 and 9.
In another aspect, the invention provides an isolated nucleic acid encoding the mutated HPV11 L1 protein or a variant thereof as described above. In another aspect, the invention provides a vector comprising the isolated nucleic acid. In some preferred embodiments, the isolated nucleic acid according to the invention has a nucleotide sequence selected from the group consisting of: SEQ ID NOs: 13, 14 and 16.
Vectors useful for insertion of a polynucleotide of interest are well known in the art, including, but not limited to cloning vectors and expression vectors. In one embodiment, the vectors are, for example, plasmids, cosmids, phages, etc.
In another aspect, the invention further relates to a host cell comprising the isolated nucleic acid or the vector. The host cell includes, but is not limited to prokaryotic cells such as E. coli cells, and eukaryotic cells such as yeast cells, insect cells, plant cells and animal cells (such as mammalian cells, for example, mouse cells, human cells, etc.). The host cell according to the invention may also be a cell line, such as 293T cell.
In another aspect, the invention relates to a HPV virus-like particle comprising or consisting of the mutated HPV11 L1 protein or a variant thereof according to the invention.
In some preferred embodiments, the HPV virus-like particle according to the invention comprises the mutated HPV11 L1 protein, which has N-terminal truncation of 3-6 amino acids, for example, 3, 4, 5 or 6 amino acids, as compared to a wild type HPV11 L1 protein, and substitution of the amino acid residues at positions 170-179 of the wild type HPV11 L1 protein with the amino acid residues at positions 169-178 of a wild type HPV6 L1 protein.
In some preferred embodiments, the HPV virus-like particle according to the invention comprises the mutated HPV11 L1 protein, which has N-terminal truncation of 3-6 amino acids, for example, 3, 4, 5 or 6 amino acids, as compared to a wild type HPV11 L1 protein, and substitution of the amino acid residues at positions 346-351 of the wild type HPV11 L1 protein with the amino acid residues at positions 345-350 of a wild type HPV6 L1 protein.
In some preferred embodiments, the HPV virus-like particle according to the invention comprises the mutated HPV11 L1 protein, which has N-terminal truncation of 3-6 amino acids, for example, 3, 4, 5 or 6 amino acids, as compared to a wild type HPV11 L1 protein, and substitution of amino acid residues at positions 119-140 of the wild type HPV11 L1 protein with the amino acid residues at positions 119-139 of a wild type HPV6 L1 protein.
In a particularly preferred embodiment, the HPV virus-like particle according to the invention comprises the mutated HPV11 L1 protein, which has a sequence as set forth in SEQ ID NO: 6, 7 or 9.
In another aspect, the invention further relates to a composition comprising the mutated HPV11 L1 protein or a variant thereof, the isolated nucleic acid, the vector, the host cell, or the HPV virus-like particle. In some preferred embodiments, the composition comprises the mutated HPV11 L1 protein or a variant thereof according to the invention. In some preferred embodiments, the composition comprises the HPV virus-like particle according to the invention.
In another aspect, the invention further relates to a pharmaceutical composition or vaccine, comprising the HPV virus-like particle according to the invention, and optionally a pharmaceutically acceptable carrier and/or excipient. The pharmaceutical composition or vaccine according to the invention can be used for preventing HPV infection, or a disease caused by HPV infection, such as cervical cancer and condyloma acuminatum.
In some preferred embodiments, the HPV virus-like particle is present in an amount effective for preventing HPV infection or a disease caused by HPV infection. In some preferred embodiments, the HPV infection is infection by one or more HPV types (e.g. HPV11 infection and/or HPV6 infection). In some preferred embodiments, the disease caused by HPV infection is selected from the group consisting of cervical cancer and condyloma acuminatum.
The pharmaceutical composition or vaccine according to the invention may be administrated by methods well known in the art, for example, but not limited to, orally or by injection. In the invention, a particularly preferred administration route is injection.
In some preferred embodiments, the pharmaceutical composition or vaccine according to the invention is administrated in a form of a unit dosage. For example, but not for limiting the invention, each unit dosage contains 5 μg-80 μg, preferably 20 μg-40 μg of HPV virus-like particle.
In another aspect, the invention relates to a method for preparing the mutated HPV11 L1 protein or a variant thereof as described above, comprising expressing the mutated HPV11 L1 protein or a variant thereof in a host cell, and then recovering the mutated HPV11 L1 protein or a variant thereof from a culture of the host cell.
In some preferred embodiments, the host cell is E. coli. 
In some preferred embodiments, the method comprises the steps of: expressing the mutated HPV11 L1 protein or a variant thereof in E. coli, and then obtaining the mutated HPV11 L1 protein or a variant thereof by purifying a lysate supernatant of the E. coli. In some preferred embodiments, the mutated HPV11 L1 protein or a variant thereof is recovered from the lysate supernatant of the E. coli by chromatography (e.g. cation-exchange chromatography, hydroxyapatite chromatography and/or hydrophobic interaction chromatography).
In another aspect, the invention relates to a method for preparing a vaccine, comprising combining the HPV virus-like particle according to the invention with a pharmaceutically acceptable carrier and/or excipient.
In another aspect, the invention relates to a method for preventing HPV infection or a disease caused by HPV infection, comprising administering to a subject a prophylactically effective amount of the HPV virus-like particle or the pharmaceutical composition or vaccine according to the invention. In a preferred embodiment, the HPV infection is infection by one or more HPV types (e.g. HPV11 infection and/or HPV6 infection). In another preferred embodiment, the disease caused by HPV infection includes, but is not limited to cervical cancer and condyloma acuminatum. In another preferred embodiment, the subject is mammal, such as human.
In another aspect, the invention further relates to use of the mutated HPV11 L1 protein or a variant thereof or the HPV virus-like particle according to the invention in the manufacture of a pharmaceutical composition or vaccine for preventing HPV infection or a disease caused by HPV infection. In a preferred embodiment, the HPV infection is infection by one or more HPV types (e.g. HPV11 infection and/or HPV6 infection). In another preferred embodiment, the disease caused by HPV infection includes, but is not limited to, cervical cancer and condyloma acuminatum.
Definitions of Terms in the Invention
In the invention, unless otherwise specified, the scientific and technical terms used herein have the meanings generally understood by a person skilled in the art. Moreover, the laboratory operations of cell culture, molecular genetics, nucleic acid chemistry, and immunology used herein are the routine operations widely used in the corresponding fields. Meanwhile, in order to better understand the invention, the definitions and explanations of the relevant terms are provided as follows.
According to the invention, the term “a second type of wild-type HPV” refers to a wild-type HPV type other than HPV11. In the invention, a second type of wild-type HPV is preferably wild-type HPV6.
According to the invention, the expression “corresponding positions” refers to the equivalent positions of the sequences being compared when the sequences are optimally aligned, i.e. the sequences are aligned to obtain a highest percentage of identity.
According to the invention, the term “wild type HPV11 L1 protein” refers to the naturally-occurring major capsid protein L1 in Human Papillomavirus Type 11 (HPV11). The sequence of wild type HPV11 L1 protein is well known in the art, and can be found in public database (such as HPV11 L1 protein encoded by Accession No. M14119.1, AF335603.1, AF335602.1, etc. in NCBI database).
In the invention, when an amino acid sequence of wild type HPV11 L1 protein is mentioned, it is described by reference to the sequence as set forth in SEQ ID NO: 1. For example, the expression “amino acid residues at positions 170-179 of a wild type HPV11 L1 protein” refers to the amino acid residues at positions 170-179 of the polypeptide as set forth in SEQ ID NO: 1. However, a person skilled in the art understands that wild type HPV11 may include various isolates, and there might be difference in the amino acid sequence of L1 protein among various isolates. Furthermore, a person skilled in the art understands that although there might be difference in sequence, the amino acid sequences of L1 protein have a very high identity (generally higher than 95%, e.g. higher than 96%, higher than 97%, higher than 98%, or higher than 99%) among different HPV11 isolates, and have substantively the same biological function. Therefore, in the invention, the term “wild type HPV11 L1 protein” includes not only the protein as set forth in SEQ ID NO: 1, but also L1 protein of various HPV11 isolates (such as HPV11 L1 protein encoded by Accession No. M14119.1, AF335603.1, AF335602.1, etc. in NCBI database). Moreover, when a sequence fragment of a wild type HPV11 L1 protein is described, it includes not only the sequence fragment of SEQ ID NO: 1, but also the corresponding sequence fragment of a L1 protein of various HPV11 isolates. For example, the expression “amino acid residues at positions 170-179 of a wild type HPV11 L1 protein” includes the amino acid residues at positions 170-179 of SEQ ID NO: 1, and the corresponding fragment of a L1 protein of various HPV11 isolates.
According to the invention, the term “wild type HPV6 L1 protein” refers to the naturally-occurring major capsid protein L1 in Human Papillomavirus Type 6 (HPV6). The sequence of wild type HPV6 L1 protein is well known in the art, and can be found in public database (such as HPV6 L1 protein encoded by Accession No. AF067042.1, AF092932.1, L41216.1, XOO203.1, etc. in NCBI database).
In the invention, when an amino acid sequence of wild type HPV6 L1 protein is mentioned, it is described by reference to the sequence as set forth in SEQ ID NO: 2. For example, the expression “amino acid residues at positions 169-178 of a wild type HPV6 L1 protein” refers to the amino acid residues at positions 169-178 of the polypeptide as set forth in SEQ ID NO: 2. However, a person skilled in the art understands that wild type HPV6 may include various isolates, and there might be difference in the amino acid sequence of L1 protein among various isolates. Furthermore, a person skilled in the art understands that although there might be difference in sequence, the amino acid sequences of L1 protein have a very high identity (generally higher than 95%, e.g. higher than 96%, higher than 97%, higher than 98%, or higher than 99%) among different HPV6 isolates, and have substantively the same biological function. Therefore, in the invention, the term “wild type HPV6 L1 protein” includes not only the protein as set forth in SEQ ID NO: 2, but also L1 protein of various HPV6 isolates (such as HPV6 L1 protein encoded by Accession No. AF067042.1, AF092932.1, L41216.1, XOO203.1, etc. in NCBI database). Moreover, when a sequence fragment of a wild type HPV6 L1 protein is described, it includes not only the sequence fragment of SEQ ID NO: 2, but also the corresponding sequence fragment of a L1 protein of various HPV6 isolates. For example, the expression “amino acid residues at positions 169-178 of a wild type HPV6 L1 protein” includes the amino acid residues at positions 169-178 of SEQ ID NO: 2, and the corresponding fragment of a L1 protein of various HPV6 isolates.
According to the invention, the expression “corresponding sequence fragments” or “corresponding fragments” refers to the fragments that are located in equivalent positions of the sequences being compared when the sequences are optimally aligned, i.e. the sequences are aligned to obtain a highest percentage of identity.
According to the invention, the expression “N-terminal truncation of X amino acids” or “having X amino acids truncated at N-terminal” refers to substitution of the amino acid residues from positions 1 to X at the N-terminal of a protein with methionine residue encoded by an initiator codon (for initiating protein translation). For example, a HPV11 L1 protein having 4 amino acids truncated at N-terminal refers to a protein resulted from substituting the amino acid residues from positions 1 to 4 at the N-terminal of wild type HPV11 L1 protein with methionine residue encoded by an initiator codon.
According to the invention, the term “variant” refers to a protein, whose amino acid sequence has substitution (preferably conservative substitution), addition or deletion of one or several (e.g. 1, 2, 3, 4, 5, 6, 7, 8 or 9) amino acids, or has an identity of at least 90%, 95%, 96%, 97%, 98%, or 99%, as compared with the mutated HPV11 L1 protein according to the invention (for example, the protein as set forth in SEQ ID NO: 6, 7 or 9), and which retains a function of the mutated HPV11 L1 protein. In the invention, the term “function of the mutated HPV11 L1 protein” refers to the capability of inducing the generation of neutralizing antibodies against at least two HPV types (e.g. HPV11 and HPV6). The term “identity” refers to a measure of similarity between nucleotide sequences or amino acid sequences. Generally, sequences were aligned to obtain a maximum matching. “Identity” has well-known meanings in the art and can be calculated by published algorithm (such as BLAST).
According to the invention, the term “identity” refers to the match degree between two polypeptides or between two nucleic acids. When two sequences for comparison have the same monomer sub-unit of base or amino acid at a certain site (e.g., each of two DNA molecules has an adenine at a certain site, or each of two polypeptides has a lysine at a certain site), the two molecules are identical at the site. The percent identity between two sequences is a function of the number of identical sites shared by the two sequences over the total number of sites for comparison×100. For example, if 6 of 10 sites of two sequences are matched, these two sequences have an identity of 60%. For example, DNA sequences: CTGACT and CAGGTT share an identity of 50% (3 of 6 sites are matched). Generally, the comparison of two sequences is conducted in a manner to produce maximum identity. Such alignment can be conducted by for example using a computer program such as Align program (DNAstar, Inc.) which is based on the method of Needleman, et al. (J. Mol. Biol. 48:443-453, 1970). The percent identity between two amino acid sequences can also be determined using the algorithm of E. Meyers and W. Miller (Comput. Appl. Biosci., 4:11-17 (1988)) which has been incorporated into the ALIGN program (version 2.0), using a PAM120 weight residue table, and with a gap length penalty of 12 and a gap penalty of 4. In addition, the percentage of identity between two amino acid sequences can be determined by the algorithm of Needleman and Wunsch (J. Mol. Biol. 48:444-453 (1970)) which has been incorporated into the GAP program in the GCG software package (available at http://www.gcg.com), using either a Blossum 62 matrix or a PAM250 matrix, and with a gap weight of 16, 14, 12, 10, 8, 6, or 4 and a length weight of 1, 2, 3, 4, 5, or 6.
As used herein, the term “conservative substitution” refers to amino acid substitutions which would not disadvantageously affect or change the essential properties of a protein/polypeptide comprising the amino acid sequence. For example, a conservative substitution may be introduced by standard techniques known in the art such as site-directed mutagenesis and PCR-mediated mutagenesis. Conservative amino acid substitutions include substitutions wherein an amino acid residue is substituted with another amino acid residue having a similar side chain, for example, a residue physically or functionally similar (such as, having similar size, shape, charge, chemical property including the capability of forming covalent bond or hydrogen bond, etc.) to the corresponding amino acid residue. The families of amino acid residues having similar side chains have been defined in the art. These families include amino acids having basic side chains (for example, lysine, arginine and histidine), amino acids having acidic side chains (for example, aspartic acid and glutamic acid), amino acids having uncharged polar side chains (for example, glycine, asparagine, glutamine, serine, threonine, tyrosine, cysteine, tryptophan), amino acids having nonpolar side chains (for example, alanine, valine, leucine, isoleucine, proline, phenylalanine, methionine), amino acids having β-branched side chains (such as threonine, valine, isoleucine) and amino acids having aromatic side chains (for example, tyrosine, phenylalanine, tryptophan, histidine). Therefore, generally a conservative substitution refers to a substitution of a corresponding amino acid residue with another amino acid residue from the same side-chain family. Methods for identifying amino acid conservative substitutions are well known in the art (see, for example, Brummell et al., Biochem. 32: 1180-1187 (1993); Kobayashi et al., Protein Eng. 12(10): 879-884 (1999); and Burks et al., Proc. Natl. Acad. Sci. USA 94: 412-417 (1997), which are incorporated herein by reference).
According to the invention, the term “E. coli expression system” refers to an expression system consisting of E. coli (strain) and a vector, wherein the E. coli (strain) is derived from the commercially available strains, including, but not limited to: ER2566, BL21 (DE3), B834 (DE3), and BLR (DE3).
According to the invention, the term “vector” refers to a nucleic acid carrier tool which can have a polynucleotide inserted therein. When the vector allows for the expression of the protein encoded by the polynucleotide inserted therein, the vector is called an expression vector. The vector can have the carried genetic material elements expressed in a host cell by transformation, transduction, or transfection into the host cell. Vectors are well known by a person skilled in the art, including, but not limited to plasmids, phages, cosmids, etc.
According to the invention, the term “a pharmaceutically acceptable carrier and/or excipient” refers to a carrier and/or excipient that is pharmacologically and/or physiologically compatible to a subject and active ingredients, which is well known in the art (see, for example, Remington's Pharmaceutical Sciences. Edited by Gennaro A R, 19th ed. Pennsylvania: Mack Publishing Company, 1995), including, but not limited to: pH regulators, surfactants, adjuvants, and ionic strength enhancers. For example, pH regulators include, but are not limited to, phosphate buffers; surfactants include, but are not limited to: cation surfactants, anion surfactants, or non-ionic surfactants, e.g., Tween-80; adjuvants include, but are not limited to, aluminium adjuvant (e.g., aluminium hydroxide), and Freund's adjuvant (e.g., Freund's complete adjuvant); and ionic strength enhancers include, but are not limited to, NaCl.
According to the invention, the term “an effective amount” refers to an amount that can effectively achieve the intended purpose. For example, an amount effective for preventing a disease (such as HPV infection) refers to an amount effective for preventing, suppressing, or delaying the occurrence of a disease (such as HPV infection). The determination of such an effective amount is within the ability of a person skilled in the art.
According to the invention, the term “chromatography” includes, but is not limited to: ion exchange chromatography (such as cation-exchange chromatography), hydrophobic interaction chromatography, absorbent chromatography (such as hydroxyapatite chromatography), gel filtration chromatography (gel exclusion chromatography), and affinity chromatography.
According to the invention, the term “lysate supernatant” refers to a solution produced by the following steps: host cells (such as E. coli) are disrupted in a lysis buffer, and the insoluble substances are then removed from the lysed solution containing the disrupted host cells. Various lysis buffers are well known in the art, including, but not limited to Tris buffers, phosphate buffers, HEPES buffers, MOPS buffers, etc. In addition, the disrupting of a host cell can be accomplished by methods well known by a person skilled in the art, including, but not limited to homogenizer disrupting, ultrasonic treatment, grinding, high pressure extrusion, lysozyme treatment, etc. Methods for removing insoluble substances are also well known by a person skilled in the art, including, but not limited to filtration and centrifugation.
Beneficial Effects of Invention
Studies show that although there is certain cross-protection between HPV11 and other HPV type(s) (such as HPV6), such cross-protection is very low, generally lower than one percent, even one thousandth of the protection level of VLP of the same HPV type. Therefore, a subject vaccinated with HPV11 vaccine, still has a high risk of being infected by other HPV type(s) (such as HPV6).
The invention provides a mutated HPV11 L1 protein and a HPV virus-like particle formed by the same. The HPV virus-like particle according to the invention can provide significant cross-protection against HPV11 and other HPV type(s) (such as HPV6). Especially, at the same immunizing dose, the HPV virus-like particle according to the invention can induce the generation of high-titer neutralizing antibodies against at least two HPV types (e.g. HPV11 and HPV6) in organisms, and its effect is comparable to that of a mixture of VLPs of multiple HPV types (e.g. a mixture of HPV11 VLP and HPV6 VLP). Therefore, the HPV virus-like particle according to the invention can be used to prevent infection by at least two HPV types (e.g. HPV11 and HPV6) at the same time as well as diseases associated with the infection, and has significantly beneficial technical effects. This has particularly significant advantages in terms of extending the protection range of HPV vaccines and reducing the production cost of HPV vaccines.
The embodiments of the invention are further described in detail by reference to the drawings and examples. However, a person skilled in the art would understand that the following drawings and examples are intended for illustrating the invention only, rather than defining the scope of the invention. According to the detailed description of the following drawings and preferred embodiments, various purposes and advantages of the invention are apparent for a person skilled in the art.